Feed valve device



Dec. 20, 1932 D. F. BROWN FEED VALVE DEVICE Filed March 20, 1929 Figl 20 /9 2; t 6 ll) :5

INVENTOR DONALD FTBROWN ATTORNEY Patented Dec. 20, 1932 I UNITED" STATES DONALD 1. BROWN, OF Lo Do ENGLAND, ASSIGNOR TO THE wnsTINGnousi: A13

7 DRAKE COMPANY, or ILMERD-ING,rn Ns LvANIA, A CORPORATION or PENN- SYLVANIA man VALVE DEVIC Application filed March 20,192 Serial No. 348,537, and in Great Britain Ju1y 18, 1 92s.

This invention relates to feed valves for fluid pressure braking apparatus of .the kind comprising a supply valve actuated by a piston or other form of movable abutment, from one side of which fluid under pressure is vented to cause the piston to open the valve, the release of fluid from the abutment being controlled by an automatic regulating device responsive to variations in train pipe pressure, the'invention having for its object to provide an improved feed valve of this character. 7

1n the'usual construction of the feed valve of the type to which the invention relates, the valve when opened by the action of fluid under pressure acting on one side of the piston due to the reduction of pressure on the opposite side thereof is caused to return under the action of a spring to its closedposition when the release of fluid is interrupted, the fluid pressure on the two sides of the piston being equalized by leakage past the piston. The passage of fluid under pressure from one side to the other of the piston in this manner to permit the valve to close is found in practice to be somewhat uncertain and variable being dependentupon the closeness of the fit of the piston which is liable to considerable variation in service and due to the presence of oil, dust and other foreign matter.

The present invention accordingly contemplates the use of an independent by-pass or release passage establishing permanent restricted communication between the two sides of the piston or other form of abutment, this communication being so arranged as to afford a passage of vdefinite and constant capacity for the passage of fluid from one side of the abutment to the other, the construction being such, moreover, that liability to ob struction or variation of the resistance to the flow of fluid through the release passage by the accumulation of dirt, oil or other foreign matter is reduced to a minimum, while the portion of the by-pass passage constituting the restricted portion is capable of being readily examined, cleaned or replaced.

In the accompanying drawing: Figure 1 is a sectional view of a feed valve device embodying'my invention; andFig. 2 a section on the line 2-2 of Fig. 1'.

PATENT. OFFICE 1 In order that the nature of the invention may be clearly understood, a preferred construction of feed valve embodying one form of the invention will now be described by wayof'example;

The feed valve comprises the usual piston 1 for actuatingthe supply valve 2 ofthe device,-this piston being adapted to move in a cylinder forming a portion of the feed valve body 5 and provided with a suitable cylindrical liner 3. The by-pass or release passageis formed in an extension 4 of the valve body-5 at one side ofthe cylinder, the chamber' 6 at the lower portion of this extension communicating, by a passage 7 formed in the body, with the valve chamber 8-. The chamber 6 of the extension 1 is closed from below by a cylindrical screw-threaded plug 9', the

inner end of which forms a cylindrical open ended cup 10 having at the base thereof'a conical projection 11 co-axial with the cylindrical extension. V i

The cup 10 abovereferred to, when the plug. 9 is in position, is locatedv within the cyln'idric'al chamber 6, the lower portion of which adjacent to the base of the cup is in" communication with the valvechamber 8 by the passage 7 above referred to. The cup 10 is, provided with one or more apertures 12. ad acent to the base thereof, so as to permit any dust or oil accumulating within the cup 10 to pass directly to the base of the cylindrical chamber 6 in which the cup is located.

The upper end of this cylindrical chamber 6 is provided with a removable nozzle element comprising a cylindrical screw-threaded plug 13, the lower end of which is conical with the coned end 14 of the plug arranged within the cup 10 above referred to and separated by a short distance from the end of the conical extension 11 on thelower'plug 9 above de scribed. The cylindrical plug 13 forming the nozzle element is traversed by an axial passage 15, connectingatthe lower part with a passage 16 of relatively small diameter which extends to the apex of the lower conical end 14 ofthe element, the passage being preferably closed at this end by'means of a small plug 17 Communication between the interior of the cup and the axial passage in the nozzle element is effected by a number of transverse passages 18 terminating at the coned face of the nozzle element and communicating with the restricted axial passage 16 thereof.

The nozzle element above referred to Yes,- tablishes communication between the cylindrical chamber 6 containing the cup and the chamber 19 of the cylindrical extension 4, through the by-pass passage 15, this upper chamber being closed by a suitable cap or plug 20 surrounding and enclosing the upper end of the nozzle element 13. This upper chamber 19 isrin communication with the chamber 21 above the piston 1 of the device by means of a suitable transverse passage 22.

In operation, it will be understood that when fluid under pressure is released from the upper face of the piston 1, said piston operates in the usual manner to open the supply valve 2 and when this release of fluid is interrupted, fluid under pressure then passes around the piston 1 through the bypass pas sage including the nozzle element 13. I

It will be seen that the nozzle element 13 above referred to provides a by-pass passage of definite .restricted'capacity establishing permanent communication from one side of the piston 1 to the other side, and owing to the provision of the transverse passages 18 terminating at the coned face of the nozzle element 13 and to the provision of the cup 10, the path of the fluid through the by-pass passage is such as to necessitate relatively sharp variations of direction in the flow of fluid, thereby causing any lubricant or dust present to be deposited at the base of the cup 10 or in the base of the surrounding chamber 6 in the lower part of the cylindricalextension 4:

without risk of affecting the capacity of the by-pass passage. By removing the lower plug 9, the cup 10 and the surrounding chamher 6 can be readily inspected and cleaned, while by removing the upper cap or plug 20, the nozzle element 13, the upper end of which is of hexagonal or square cross section, can be removed from its position, and the passages in the nozzle element examined and cleaned if necessary.

In view of the foregoing, it will be evident that flow of fluid under pressure between the piston chamber 21 and thevalve chamber 8 is controlled by the restricted passages 18 in the nozzle 'end of the plug 18, and since the nozzle extends into the cup 10, foreign matter will be deposited at the base of the cup. The member carrying the cup 10 can be removed for cleaning without removing the nozzle.

The invention is evidently not limited to the particular construction, arrangement and relative location of the parts as above described, and variations in any of these re spects may be made without exceeding the scope of the invention.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is

1. A casing having two chambers, one of which is normally charged with fluid under pressure, a plug mounted in said casing and having a restricted passageway through which fluid underpressure is supplied from the normally charged chamber to the other chamber, the end of said plug extending into a space communicating with the normally charged chamber, and a member removably mounted in said casing and having a cupshaped wall extending into said space and surrounding said end of the plug, said member being removable independently of and without removing said plug.

2. A casing having two chambers, one of which is normally charged with fluid under pressure, a plug mounted in said casingand having a restricted passageway through which fluid under pressure is supplied from the normally charged chamber to the other chamber, the end of said plug extending into a space communicating with the normally charged chamber, said plug being removable, and a member removably mounted in said casing and removable in the opposite direction from the plug, and having a cup-shaped wall extending into said space and surrounding said end of the plug.

In testimony whereof I have hereunto set my hand, c

DONALD F. BROWN. 

